In #15080, there was a command added to re-add 127.0.0.1/8 to the lo
interface when the networking configuration is being brought down.
However, the trigger for that command is `down`, which, looking at
ifupdown2 configuration files, runs immediately after 127.0.0.1/16 is
removed. This means there may be a period of time where there are no
loopback addresses assigned to the lo interface, and redis commands will
fail.
Fix this by changing this to pre-down, which should run well before
127.0.0.1/16 is removed, and should always leave lo with a loopback
address.
Signed-off-by: Saikrishna Arcot <sarcot@microsoft.com>
Co-authored-by: Saikrishna Arcot <sarcot@microsoft.com>
* Re-add 127.0.0.1/8 when bringing down the interfaces
With #5353, 127.0.0.1/16 was added to the lo interface, and then
127.0.0.1/8 was removed. However, when bringing down the lo interface,
like during a config reload, 127.0.0.1/16 gets removed, but 127.0.0.1/8
isn't added back to the interface. This means that there's a period of
time where 127.0.0.1 is not available at all, and services that need to
connect to 127.0.01 (such as for redis DB) will fail.
To fix this, when going down, add 127.0.0.1/8. Add this address before
the existing configuration gets removed, so that 127.0.0.1 is available
at all times.
Note that running `ifdown lo` doesn't actually bring down the loopback
interface; the interface always stays "physically" up.
Signed-off-by: Saikrishna Arcot <sarcot@microsoft.com>
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#### Why I did it
The tests that are available for interfaces.j2 only covers the case when ZTP is disabled and MGMT_INTERFACE is defined. This change adds unit tests for:
1) When ZTP is enabled, with combination of (ip enabled/disabled, inband enabled/disabled)
2) When ZTP is disabled, and MGMT_INTERFACE is not defined, with mgmtVrfEnabled set to true/false
#### How I did it
I created multiple mock-up files to:
1) Enable/disable ZTP, and subconditions under ZTP
2) Created graph file that has no management interface defined
#### How to verify it
Compared output with interfaces.j2 template to ensure the output is expected.
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- [ ] 201811
- [ ] 201911
- [ ] 202006
- [ ] 202012
- [ ] 202106
- [ ] 202111
- [ ] 202205
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